Narrowband IoT: Your Definitive Guide to NB-IoT

NB-IoT is a Low Power Wide Area Network (LPWAN) technology designed to enable efficient communication between a vast number of devices over long distances. This cellular technology operates on licensed spectrum, providing enhanced coverage and reliability for IoT applications.

Published on September 18, 2024

Narrowband IoT: Your Definitive Guide to NB-IoT

While most consumer electronic devices thrive on high speeds and high data bandwidth, it’s easy to overlook the quiet technological revolution happening in the background—one that isn’t focused on faster downloads or ultra-HD streaming. Instead, this revolution is all about connecting the things that need less: less data, less power, less complexity.

Enter Narrowband IoT (NB-IoT), the unsung hero of the Internet of Things world. NB-IoT isn’t about flashy, data-heavy apps; it’s about making sure your smart thermostat stays connected for months on a single battery or helping a sensor deep in the belly of a building monitor its surroundings without draining energy. If you’ve ever wondered how billions of tiny devices will stay online without costing a fortune or gobbling up bandwidth, NB-IoT is the answer. It’s small, it's efficient, and it's powering the invisible infrastructure of our connected future.

What is NB-IoT?

As cities grow smarter and industries become more interconnected, NB-IoT is emerging as a crucial player in the development of sustainable, productive, and comfortable urban environments.

NB Iot Benefits

What are the Benefits of NB-IoT?

NB-IoT offers several significant benefits that make it an attractive technology for various IoT applications, including extended coverage & penetration, long battery life, cost-effectiveness, scalability, and usage in a variety of applications.

● Extended Coverage and Penetration: NB-IoT provides superior coverage compared to traditional cellular networks, allowing devices to communicate effectively in challenging environments. This technology can penetrate deep into buildings, basements, and rural areas, making it ideal for applications that require connectivity in hard-to-reach locations.

● Long Battery Life: One of the most notable advantages of NB-IoT is its ability to dramatically extend device battery life. The low-power consumption of NB-IoT enables IoT devices to operate for years on a single battery charge, making it suitable for remote or hard-to-access installations.

● Cost-Effectiveness: NB-IoT is designed to be a cost-effective solution for IoT deployments. The simplified design of NB-IoT modules makes them more affordable to manufacture and deploy at scale, opening up new possibilities for widespread IoT adoption.

● Wide Range of Applications: The technology's versatility allows it to be used across various industries and applications, including agriculture, smart applications, power engineering, medical, and industrial.

● Improved Connectivity: NB-IoT can enhance connectivity in areas where traditional Wi-Fi coverage is limited. It can be used to extend the range of Wi-Fi zones, improving overall IoT connectivity.

● Reliability and Quality of Service: Operating on licensed spectrum, NB-IoT offers enhanced reliability and quality of service compared to some other IoT technologies. This makes it suitable for applications that require consistent and dependable communication.

● Scalability: NB-IoT is designed to support a massive number of connected devices, making it ideal for large-scale IoT deployments in smart cities, industrial settings, and other scenarios requiring extensive device networks.

By offering these benefits, NB-IoT addresses many of the challenges faced in IoT deployments, particularly in terms of coverage, battery life, and cost-effectiveness. As the technology continues to mature, it is expected to play a crucial role in enabling the widespread adoption of IoT across various sectors.

How Does NB-IoT Work?

To understand how NB-IoT works, let's delve into its technical aspects, such as spectrum and bandwidth, modulation and data rates, protocol stack, coverage enhancement, power saving mechanisms, and more.

Spectrum and Bandwidth

NB-IoT operates in licensed spectrum, typically using a small bandwidth of 180 kHz. It can be deployed in three modes:

● In-band: Using resource blocks within an LTE carrier

● Guard-band: Utilizing the unused resource blocks within an LTE carrier's guard-band

● Standalone: Using its own dedicated carrier, often by refarming a GSM carrier

Modulation and Data Rates

NB-IoT uses QPSK modulation for downlink and either QPSK or BPSK for uplink transmissions. The technology supports peak data rates of:

● Downlink: 250 kbps

● Uplink: 20-250 kbps (depending on the deployment mode and number of tones used)

NB-IoT Protocol Stack

NB-IoT employs a simplified protocol stack compared to traditional LTE, optimized for low-power and low-complexity devices. The stack includes:

Physical Layer (PHY)
Medium Access Control (MAC)
Radio Link Control (RLC)
Packet Data Convergence Protocol (PDCP)
Radio Resource Control (RRC)

Coverage Enhancement

NB-IoT achieves extended coverage through repetition and power boosting techniques. It can provide up to 164 dB of maximum coupling loss (MCL), allowing for deep indoor penetration and extended range.

Power Saving Mechanisms

NB-IoT incorporates several power-saving features to extend battery life:

● Power Saving Mode (PSM): Devices can enter a deep sleep state while maintaining network registration.

● Extended Discontinuous Reception (eDRX): Allows devices to sleep for longer periods between paging occasions.

● Release Assistance Indication (RAI): Enables devices to indicate when they have no more data to send, allowing the network to release radio resources quickly.

Positioning & Multicast Capability

NB-IoT supports various positioning methods, including:

Cell ID (CID)
Observed Time Difference of Arrival (OTDOA)
Enhanced Cell ID (E-CID)

These methods can provide location accuracy ranging from tens to hundreds of meters, depending on the specific technique and environment. Additionally, in 3GPP Release 14, NB-IoT introduced multicast capabilities, allowing for efficient delivery of data to multiple devices simultaneously.

Security & Network Architecture

NB-IoT inherits the robust security features of LTE, including:

● Mutual authentication between device and network

● Encryption of user data and signaling

● Integrity protection of signaling

NB-IoT can be integrated into existing LTE infrastructure, utilizing the Evolved Packet Core (EPC) for core network functions. However, as IoT requirements grow, there are ongoing efforts to optimize the architecture for 5G integration. This may include cloud-native core network functions, network slicing for dedicated IoT services, and edge computing for reduced latency and improved efficiency.

Device Classes

NB-IoT supports different device power classes, with Release 14 introducing a lower power class (Class 6) with a maximum transmit power of 14 dBm, further improving energy efficiency for certain use cases. This power class reduces peak consumption, which has a positive impact on overall battery life.

In summary, NB-IoT works by utilizing a narrow bandwidth within licensed spectrum, employing simplified protocols, and incorporating various power-saving and coverage enhancement techniques to provide efficient, long-range communication for IoT devices. Its design allows for seamless integration with existing cellular networks while offering the flexibility to evolve towards 5G architectures.

NB IoT Availability

Regional Availability of NB-IoT

The availability of NB-IoT varies across different countries, with some regions having more extensive coverage than others. Many European countries have seen significant NB-IoT deployment. For example, in Portugal, a study conducted in the North region showed that NB-IoT technology is capable of satisfying the requirements of demanding IoT applications, with successful transmission rates above 96%, even at distances greater than 1400m (.87 miles) between the device and the LTE cell.

For South America, a comparison study between LoRa and NB-IoT coverage was conducted in urban and rural Southern Brazil regions, indicating that NB-IoT is available in at least some parts of the country.

While specific country data is limited in regards to developing countries, it's worth noting that many developing countries are looking to leverage IoT and wireless sensor networks for sustainable smallholder agriculture. However, there are still significant gaps in the utilization of these technologies due to social, economic, infrastructural, and technological barriers.

Coverage Characteristics

● Urban vs. Rural: NB-IoT coverage tends to be more extensive in urban areas compared to rural regions. This is partly due to the existing cellular infrastructure that NB-IoT can leverage.

● Indoor and Underground Coverage: NB-IoT has shown capabilities for indoor and underground coverage. A study in Portugal demonstrated successful transmissions in various challenging environments, including indoor, underground, and inside an underground concrete dome with an iron cover.

● Remote Areas: While NB-IoT aims to provide wide coverage, there are still challenges in very remote or isolated areas. Some companies are exploring satellite-based IoT solutions to complement terrestrial networks in these regions.

Factors Affecting NB-IoT Availability

● Network Operator Deployment: The availability of NB-IoT largely depends on the rollout efforts of telecom operators in each country.

● Regulatory Environment: Different countries have varying regulations regarding spectrum allocation and IoT deployments, which can affect NB-IoT availability.

● Market Demand: The adoption rate of IoT applications in different sectors (e.g., agriculture, smart cities, industrial IoT) can drive the expansion of NB-IoT networks.

It's important to note that the NB-IoT landscape is rapidly evolving, with ongoing deployments and improvements in many countries. For the most up-to-date and specific information on NB-IoT availability in a particular country or region, it's best to consult local telecom operators or regulatory bodies.

Security Considerations For NB-IoT

NB-IoT offers a myriad of benefits, but also presents numerous security concerns, which you’ll find outlined in detail below.

Authentication and Access Control

NB-IoT devices require robust authentication mechanisms to prevent unauthorized access. However, implementing strong authentication can be challenging due to the limited computational resources of these devices. Common concerns include weak or default credentials, lack of multi-factor authentication, and insufficient key management practices. To address these challenges, technical solutions such as lightweight authentication protocols, hardware-based security elements (e.g., secure enclaves), and device identity management systems can be implemented.

Data Confidentiality and Integrity

Ensuring the confidentiality and integrity of data transmitted over NB-IoT networks is crucial, particularly for sensitive applications. Key concerns include eavesdropping on radio interfaces, man-in-the-middle attacks, and data tampering during transmission. To combat these threats, implementing end-to-end encryption, using robust cryptographic algorithms suitable for constrained devices, and employing message authentication codes (MACs) for integrity verification are essential technical strategies.

Network Security

The NB-IoT network infrastructure can be a target for attacks, potentially compromising the entire ecosystem. Common concerns include Denial of Service (DoS) attacks, signaling storms, and rogue base stations. Technical considerations for network security include implementing network-level intrusion detection systems, employing rate-limiting and traffic-shaping techniques, and securing core network elements with proper access controls and monitoring.

Device Security

NB-IoT devices are often deployed in remote or unattended locations, making them vulnerable to physical tampering and software attacks. Concerns include physical tampering with devices, firmware manipulation, and side-channel attacks. To mitigate these risks, secure boot mechanisms, tamper-resistant hardware, and over-the-air (OTA) firmware updates with integrity checks can be employed.

Privacy Concerns

The massive data collection capabilities of NB-IoT devices raise significant privacy issues. These include unauthorized data collection, user profiling, and tracking, as well as concerns about data retention and storage practices. Privacy can be protected by implementing data minimization techniques, using privacy-preserving protocols (e.g., differential privacy), and ensuring compliance with data protection regulations like GDPR.

Protocol-Specific Vulnerabilities

NB-IoT uses specific protocols that may have inherent vulnerabilities or implementation flaws. Concerns include the exploitation of NB-IoT signaling protocols, vulnerabilities in the Non-Access Stratum (NAS) protocol, and weaknesses in the Radio Resource Control (RRC) protocol. Technical solutions involve regular security audits of protocol implementations, protocol fuzzing techniques to identify vulnerabilities, and keeping protocol stacks up-to-date with security patches.

Key Management

Efficient and secure key management is crucial for maintaining the overall security of NB-IoT systems. Major concerns include keys being compromised, inefficient key distribution mechanisms, and a lack of forward secrecy. Robust key derivation functions, hardware security modules (HSMs) for key storage, and dynamic key rotation mechanisms are technical strategies that can help address these issues.

Scalability of Security Solutions

As NB-IoT networks grow, security solutions must scale accordingly without compromising performance. Concerns include an increased attack surface, performance degradation due to security overhead, and challenges in managing security for massive numbers of devices. To address these concerns, implementing distributed security architectures, using lightweight cryptographic primitives, and employing efficient security policy management systems are key technical considerations.

Cross-Layer Security

NB-IoT security needs to be addressed across multiple layers of the protocol stack. Concerns arise from the lack of coordination between security measures at different layers and the potential exploitation of inter-layer vulnerabilities. Solutions include implementing cross-layer security frameworks, employing holistic security analysis techniques, and designing integrated security solutions that cover physical, network, and application layers.

Regulatory Compliance

NB-IoT deployments must adhere to various regulatory requirements, which can vary by region and application domain. Concerns include varying compliance requirements across jurisdictions and the challenge of implementing security measures while maintaining compliance. Solutions include configurable security policies to adapt to different regulatory environments, regular security audits, and developing standardized security frameworks that align with common regulatory requirements.

Addressing these security concerns requires a multi-faceted approach involving hardware security measures, robust software implementations, and comprehensive security policies. As NB-IoT technology continues to evolve, ongoing research and development in security solutions will be crucial to ensure the safe and reliable operation of NB-IoT networks and devices.

Applications of NB-IoT

Narrowband Internet of Things (NB-IoT) technology has a wide range of applications across various industries due to its low power consumption, extended coverage, and ability to connect a massive number of devices. Below, you’ll find an overview of common NB-IoT applications with specific examples:

Application Area	NB-IoT Use Cases
Smart Cities	Smart street lighting adjusts brightness based on conditions, waste management with bin sensors for optimized routes, and smart parking systems guide drivers to available spaces.
Industrial IoT (IIoT)	Supports remote monitoring (temperature, pressure, leaks), asset tracking in warehouses, predictive maintenance, and efficiency improvements in manufacturing plants.
Agriculture & Environmental Monitoring	Enables soil moisture sensors for irrigation, weather stations for climate data, and air quality monitoring in urban areas.
Healthcare & Medical Devices	Remote patient monitoring via wearables, asset tracking for medical equipment, and smart pill dispensers that track adherence.
Energy Management	Smart metering systems for electricity, gas, water with automated readings, and energy management systems in commercial buildings.
Transportation & Logistics	Fleet management (vehicle tracking, cargo monitoring for sensitive goods), and bike-sharing systems with smart locks and tracking.
Safety & Security	Remotely connected smoke detectors, fire alarms, personal safety devices, and security systems for remote locations.
Infrastructure Monitoring	Monitors critical infrastructure (bridges, pipelines), tracks structural integrity, detects leaks, and monitors water levels for flood prediction.
Retail & Vending	Supports inventory tracking, smart vending machines that report stock levels, and digital signage systems with remote content management.

These applications demonstrate the versatility of NB-IoT technology across various sectors. The ability to connect a large number of devices with low power consumption and extended coverage makes NB-IoT particularly suitable for scenarios where devices need to operate for long periods without frequent battery replacements or in areas with challenging network conditions.

Final Thoughts on NB-IoT

As we conclude our exploration of Narrowband IoT (NB-IoT), it's clear that this technology is poised to play a pivotal role in shaping the future of connected devices and smart solutions across various industries.

NB-IoT's unique combination of extended coverage, low power consumption, and cost-effectiveness makes it an ideal choice for a wide range of IoT applications. From smart cities and industrial monitoring to healthcare and environmental management, NB-IoT is enabling innovative solutions that were previously impractical or impossible.

Looking Ahead

As the technology continues to mature and evolve, we can expect to see:

● Increased adoption across industries

● Further improvements in battery life and device longevity

● Enhanced integration with 5G networks and edge computing solutions

● More sophisticated security measures to address emerging threats

If you’re looking to integrate an NB-IoT solution into their end design, it’s critical to work with a partner with experience in device security, software and hardware integration, and RF testing and certification that can set your product up for success. Ezurio is your connectivity expert with decades of experience in wireless design, experience that is all rolled up into our Pinnacle™ 100 Cellulcar LTE-M / NB-IoT / Bluetooth 5 modem.

Additionally, Ezurio offers a packaged cellular gateway based on the Pinnacle 100, the MG100 Micro-Gateway. The MG100 is designed to gather sensor data via the onboard Bluetooth 5 radio, and then send that data to the cloud via cellular (LTE-M/NB-IoT) connection. The Pinnacle 100 and MG100 utilize MQTT via the Zephyr IP stack to send and receive data in a standardized packet format that is light on bandwidth and suitable for machine-to-machine applications.

The Pinnacle 100 and MG100 also leverage our Canvas Software Suite, our value-added software offering that enables easy MCU-based wireless software development. Complete with sample python scripts for BLE, MQTT, HTTPS, and LWM2M connectivity, Canvas helps our customers build wireless IoT applications in days instead of months. Additionally, deployment tools include our mobile app to update device firmware, as well as remote debugging via the Memfault embedded SDK. And all of this is backed up by our global support organization, with experience bringing products to life in the regions our products are globally certified, such as FCC, ISED, EU, UKCA, and more.

Frequently Asked Questions About NB-IoT

Is NB-IoT better than LTE-M?

NB-IoT and LTE-M are both LPWAN technologies designed for IoT applications, but each has different characteristics that make them better suited for particular use cases. NB-IoT operates on narrow bandwidth, offering lower data rates (250 kbps) and higher latency, making it ideal for stationary or low-mobility applications that require minimal power, such as sensors or devices that need to last for years on battery power. It also excels in coverage, particularly in challenging environments like basements or rural areas, but it does not support voice communications.

On the other hand, LTE-M offers higher data rates (up to 1 Mbps), lower latency, and supports mobility, making it suitable for real-time applications and mobile devices. It also provides voice capabilities through VoLTE, making it a better choice for use cases requiring frequent data transmission or voice support. Ultimately, the choice between NB-IoT and LTE-M depends on the specific needs of the IoT application, whether it prioritizes low power and extended coverage or higher speed and mobility.

What is the difference between NB-IoT and LoRaWAN?

NB-IoT and LoRaWAN are both popular LPWAN technologies for IoT, but they differ significantly in their operation and ideal use cases. NB-IoT operates in licensed spectrum, typically within cellular bands, and utilizes existing cellular infrastructure, often deployed by telecom operators. It offers higher data rates (up to 250 kbps) and generally lower latency compared to LoRaWAN. However, it also consumes more power and may have higher associated costs due to the use of licensed spectrum and cellular infrastructure. In contrast, LoRaWAN operates in unlicensed ISM bands, requires its own network infrastructure, and provides lower data rates (0.3 to 50 kbps), but is known for extremely low power consumption, making it ideal for long battery life applications.

In terms of coverage, NB-IoT performs well in urban areas with existing cellular infrastructure, while LoRaWAN excels in rural areas and can achieve longer range in certain scenarios. LoRaWAN is also generally more cost-effective due to its simpler infrastructure and unlicensed spectrum use. The choice between the two technologies depends on specific requirements: NB-IoT is better suited for applications needing higher data rates, lower latency, or cellular integration, while LoRaWAN is ideal for applications prioritizing the lowest power consumption, long range, and lower data rates.

Is NB-IoT open source?

NB-IoT itself is not open-source, as it is a standardized technology developed by 3GPP. However, several open-source initiatives and projects are related to NB-IoT, providing open implementations of various components within the NB-IoT ecosystem. These efforts are valuable for researchers and developers, offering a way to explore and prototype NB-IoT applications without relying solely on proprietary solutions.

One notable project is OpenAirInterface (OAI) NB-IoT eNB, an initiative by the OpenAirInterface Software Alliance (OSA) to develop a software-defined-radio-based NB-IoT Evolved Node B (eNB). This implementation helps users validate research ideas and test real-world applications. Similarly, Sonica is an open-source prototyping platform that includes both radio access and core network components, functioning as a testbed for interacting with NB-IoT devices. Other projects include efforts to extend existing core network implementations like OpenAirInterface Core Network to support NB-IoT signaling and data transfer, as well as the development of tools like WIP, which evaluates NB-IoT Non-Terrestrial Networks as part of the open-source 5G-air-simulator.

Prototyping efforts are also being made through collaborations between industry and academia, such as a joint project by EURECOM, B-COM, and NTUST, which has developed an open-source NB-IoT eNB based on OpenAirInterface. While the NB-IoT standard remains proprietary, these open-source initiatives facilitate research, development, and testing of NB-IoT technologies, benefiting researchers, developers, and organizations interested in experimenting with or deploying NB-IoT solutions.

How Does NB-IoT Compare to 5G?

Feature	NB-IoT	5G
Spectrum and Bandwidth	Operates in 180 kHz; deployed in-band, guard-band, or standalone within LTE spectrum	Uses sub-6 GHz and mmWave; supports up to 100 MHz for sub-6 GHz, 400 MHz for mmWave
Data Rates	Downlink: Up to 250 kbps; Uplink: 20-250 kbps	Downlink: Up to 20 Gbps; Uplink: Up to 10 Gbps
Latency	Typical latency in the range of seconds; not designed for low-latency applications	Targets Ultra-Reliable Low Latency Communication (URLLC) with 1 ms latency
Device Density	Supports up to 1 million devices per square kilometer (mMTC)	Supports up to 1 million devices per square kilometer (mMTC)
Power Efficiency	Highly optimized for low power; includes Power Saving Mode (PSM) and eDRX	Includes power-saving features but generally consumes more power than NB-IoT
Coverage	Designed for extended coverage (up to 164 dB MCL)	Coverage varies; mmWave has limited range compared to sub-6 GHz
Modulation Schemes	Downlink: QPSK; Uplink: QPSK or BPSK; Rel-17 introduced 16-QAM	Supports QPSK, 16-QAM, 64-QAM, 256-QAM, and higher orders
Network Architecture	Integrated into existing LTE infrastructure; simplified core functions	Introduces Service-Based Architecture (SBA), network slicing, edge computing
Use Cases	Optimized for low-bandwidth, long-range IoT applications (e.g., sensors, meters)	Supports enhanced Mobile Broadband (eMBB), URLLC, and mMTC
Evolution Path	Evolves through 3GPP releases; Rel-17 introduced 16-QAM and increased HARQ	Rapid evolution through 3GPP releases; features like NR-U, IAB, V2X introduced